path: root/pkg/config/server.conf

[dnbd3]
; port to listen on (default: 5003)
listenPort=5003

; relative root directory for images, ending in .r[1-9][0-9]*
basePath=/mnt/storage

; artificial connection delay for connecting servers
serverPenalty=100000

; artificial connection delay for connecting clients
clientPenalty=0

; is this server a proxy? if true, requests for non-existing images will be relayed to known alt-servers
isProxy=true

; if proxy is true and an image is incomplete, should idle bandwidth be used to replicate missing blocks?
backgroundReplication=true

; minimum amount of connected clients for background replication to kick in
bgrMinClients=0

; if another proxy requests and image that we don't have, should we ask our alt-servers for it?
lookupMissingForProxy=true

; create sparse files instead of preallocating; ignored if backgroundReplication=true
; -- only recommended if cache space is small
sparseFiles=false

; if true (which is the default), images will automatically be removed from the list if they can't be accessed
removeMissingImages=true

; timeout in ms for send/recv on connections to uplink servers (used for replication)
uplinkTimeout=5000

; timeout in ms for send/recv on connections to clients (using an image on this server)
clientTimeout=15000

; set this to true to close handles of unused images after some timeout
closeUnusedFd=false

; set this to true to load files without the .r[0-9]+ extension too, assuming RID=1
vmdkLegacyMode=false

; Don't set the server flag when connecting to alt-servers
; Intended for if the proxy is used for on-client caching
pretendClient=false

; When running in proxy mode and running out of space, automatically delete oldest image(s) to make
; the newly replicated image fit. In sparse mode, this will make sure at least 2GB of free space are
; available when replicating a new image. During normal operation, it will free at least 256MB whenever
; an attempt to write more data to cache fails. In non-sparse mode, whenever a new image is replicated,
; as much space as is required to store the entire image will be made available.
; However, after startup the proxy will refuse to delete any images for the time span given below, to be
; able to gather up to date usage information for the images available. If unitless, the value is
; interpreted in seconds. Valid suffixes are m, h, d.
; Setting this to -1 disables deletion of images. If the cache partition is full, no more images will
; be replicated unless you manually free up more disk space.
autoFreeDiskSpaceDelay=10h

; Specifies whether the iSCSI server should be initialized, enabled and used upon start of DNBD3 server.
iSCSIServer=true

[limits]
maxClients=2000
maxImages=1000
maxPayload=9M
maxReplicationSize=150G

; Maximum number of bytes to prefetch when relaying client request to upstream server
maxPrefetch=256k

[logging]
; log file path and name
; comment out to disable logging to file
; protip: use SIGUSR2 to reopen log file
file=./dnbd3.log

; which type of messages to log to file
fileMask=ERROR WARNING MINOR INFO DEBUG1

; which type of messages to log to console (stdout)
consoleMask=ERROR WARNING MINOR INFO

; Valid types (warning: specifying invalid types will not yield an error!)
; ERROR     Fatal error, server will terminate
; WARNING   Major issue, something is broken but keep running
; MINOR     Minor issue, more of a hickup than serious problem
; INFO      Informational message
; DEBUG1    Debug information, used for medium verbosity
; DEBUG2    Used for debug messages that would show up a lot

; Whether timestamps should be output to console too (or just to file if false)
consoleTimestamps=false

[iscsi]
; Target name check level (warning) specifying invalid check levels will default to full
; validation!). Default is Full
; Full      Target name is checked for full standaard compliance (recommended)
; Relaxed   All invalid characters according to standard will be allowed if not an IQN, NAA or EUI.
; None      No checking at all (be careful)
TargetNameCheck=Full

; Header digest (warning) specifying invalid digest type will default to None!).
; Default is None
; CRC32C   Use CRC32C for header validation
; None     No digest and therefore no checking will be done (be careful)
HeaderDigest=None

; Data digest (warning) specifying invalid digest type will default to None!).
; Default is None
; CRC32C   Use CRC32C for data validation
; None     No digest and therefore no checking will be done (be careful)
DataDigest=None

; Login/Text Operational Session Text Key: Maximum receive DataSegmentLength.
;
* The initiator or target declares the maximum data segment length in bytes it can receive in an
; iSCSI PDU.
* The transmitter (initiator or target) is required to send PDUs with a data segment that does not
; exceed MaxRecvDataSegmentLength of the receiver. A target receiver is additionally limited by
; MaxBurstLength for solicited data and FirstBurstLength for unsolicited dataAn initiator MUST NOT
; send solicited PDUs exceeding MaxBurstLength nor unsolicited PDUs exceeding FirstBurstLength (or
; FirstBurstLength-Immediate Data Length if immediate data were sent). Valid values range from 512
; to 16777215 bytes. Default is 8192 bytes (8 KiB)
MaxRecvDataSegmentLength=8192

; Maximum number of connections allowed per session. Default is 1
MaxConnectionsPerSession=1

; Login/Text Operational Session Text Key: Maximum outstanding Ready To Transfer.
;
; The initiator and target negotiate the maximum number of outstanding R2Ts per task, excluding any
; implied initial R2T that might be part of that task. An R2T is considered outstanding until the last
; data PDU (with the F bit set to 1) is transferred or a sequence reception timeout is encountered for
; that data sequence. Allowed values range from 1 to 65536. Default is 1
MaxOutstandingR2T=1

; Login/Text Operational Session Text Key: Default time to wait.
;
; The initiator and target negotiate the minimum time, in seconds, to wait before attempting an
; explicit/implicit logout or an active task reassignment after an unexpected connection termination
; or a connection reset.
; A value of 0 indicates that logout or active task reassignment can be attempted immediately.
; Valid values are from 0 to 3600 seconds (one hour). Default is 2 seconds
DefaultTime2Wait=2

; Login/Text Operational Session Text Key: Default time to retain.
;
; The initiator and target negotiate the maximum time, in seconds, after an initial wait (Time2Wait),
; before which an active task reassignment is still possible after an unexpected connection
; termination or a connection reset.
; This value is also the session state timeout if the connection in question is the last LOGGED_IN
; connection in the session.
; A value of 0 indicates that connection/task state is immediately discarded by the target.
; Valid values are from 0 to 3600 seconds (one hour). Default is 20 seconds
DefaultTime2Retain=20

; Login/Text Operational Session Text Key: First burst length.
;
; The initiator and target negotiate the maximum amount in bytes of unsolicited data an iSCSI
; initiator may send to the target during the execution of a single SCSI command. This covers the
; immediate data (if any) and the sequence of unsolicited Data-Out PDUs (if any) that follow the
; command.
; FirstBurstLength MUST NOT exceed MaxBurstLength. Valid lengths range from 512 to 16777215 bytes.
; Default is 65536 bytes (64 KiB)
FirstBurstLength=65536

; Login/Text Operational Session Text Key: Maximum burst length.
;
; The initiator and target negotiate the maximum SCSI data payload in bytes in a Data-In or a
; solicited Data-Out iSCSI sequence. A sequence consists of one or more consecutive Data-In or
; Data-Out PDUs that end with a Data-In or Data-Out PDU with the F bit set to 1. Valid lengths
; range from 512 to 16777215 bytes. Default is 262144 bytes (256 KiB)
MaxBurstLength=262144

; Login/Text Operational Session Text Key: Initial Ready To Transfer.
;
; The InitialR2T key is used to turn off the default use of R2T for unidirectional operations
; and the output part of bidirectional commands, thus allowing an initiator to start sending data
; to a target as if it has received an initial R2T with Buffer Offset=Immediate Data Length and
; Desired Data Transfer Length=(min(FirstBurstLength, Expected Data Transfer Length) - Received
; Immediate Data Length).
; The default action is that R2T is required, unless both the initiator and the target send this
; key-pair attribute specifying InitialR2T=No. Only the first outgoing data burst (immediate data
; and/or separate PDUs) can be sent unsolicited (i.e., not requiring an explicit R2T). Default is
; true
InitialR2T=true

; Login/Text Operational Session Text Key: Immediate data.
;
; The initiator and target negotiate support for immediate data. To turn immediate data off, the
; initiator or target must state its desire to do soImmediateData can be turned on if both the
; initiator and target have ImmediateData=Yes.
; If ImmediateData is set to Yes and InitialR2T is set to Yes (default), then only immediate data
; are accepted in the first burst. If ImmediateData is set to No and InitialR2T is set to Yes,
; then the initiator MUST NOT send unsolicited data and the target MUST reject unsolicited data
; with the corresponding response code.
; If ImmediateData is set to No and InitialR2T is set to No, then the initiator MUST NOT send
; unsolicited immediate data but MAY send one unsolicited burst of Data-OUT PDUs.
; If ImmediateData is set to Yes and InitialR2T is set to No, then the initiator MAY send
; unsolicited immediate data and/or one unsolicited burst of Data-OUT PDUs.
; The following table is a summary of unsolicited data options:
;
; InitialR2T | ImmediateData | Unsolicited Data-Out PDUs | ImmediateData
; +----------+---------------+---------------------------+-------------+
; | No       | No            | Yes                       | No          |
; | No       | Yes           | Yes                       | Yes         |
; | Yes      | No            | No                        | No          |
; | Yes      | Yes           | No                        | Yes         |
;
; Default is true
ImmediateData=true

; Login/Text Operational Session Text Key: Data Protocol Data Unit (PDU) in order.
;
; "No" is used by iSCSI to indicate that the data PDUs within sequences can be in any order.
; "Yes" is used to indicate that data PDUs within sequences have to be at continuously
; increasing addresses and overlays are forbidden. Default is true
DataPDUInOrder=true

; Login/Text Operational Session Text Key: Data sequence in order.
;
; A data sequence is a sequence of Data-In or Data-Out PDUs that end with a Data-In or Data-Out
; PDU with the F bit set to 1. A Data-Out sequence is sent either unsolicited or in response to
; an R2T.
; Sequences cover an offset-range.
; If DataSequenceInOrder is set to No, data PDU sequences may be transferred in any order.
; If DataSequenceInOrder is set to Yes, data sequences MUST be transferred using continuously
; non-decreasing sequence offsets (R2T buffer offset for writes, or the smallest SCSI Data-In
; buffer offset within a read data sequence).
; If DataSequenceInOrder is set to Yes, a target may retry at most the last R2T, and an
; initiator may at most request retransmission for the last read data sequence. For this reason,
; if ErrorRecoveryLevel is not 0 and DataSequenceInOrder is set to Yes, then MaxOutstandingR2T
; MUST be set to 1. Default is true
DataSequenceInOrder=true

; Login/Text Operational Session Text Key: Error recovery level.
;
; The initiator and target negotiate the recovery level supported. Recovery levels represent a
; combination of recovery capabilities. Each recovery level includes all the capabilities of the
; lower recovery levels and adds some new ones to them.
; In the description of recovery mechanisms, certain recovery classes are specified. Allowed
; error levels are 0, 1 and 2. Default is 0
ErrorRecoveryLevel=0

[scsi]
; Valid devices types for emulated device (warning) specifying invalid types will default to direct
; access device!). Default is Direct
; Direct           Direct access device (e.g. hard drive)
; Sequential       Sequential access device (e.g. tape)
; WriteOnce        Write once device (WORM)
; ReadOnlyDirect   Read only direct access device
; OpticalMemory    Optical memory device (e.g. CD-ROM, DVD, BluRay)
; MediaChanger     Media changer device
DeviceType=Direct

; Physical block size of emulated device, rounded up to nearest power of two). Default is 512 for
; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
; physical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
PhysicalBlockSize=512

; Logical block size of emulated device, rounded up to nearest power of two). Default is 4096 for
; supporting modern systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
; logical block sizes range from 256 to 32768 bytes (32 KiB). Default is 4096 bytes (4 KiB)
LogicalBlockSize=4096

; Device is emulated as removable. Should be enabled for CD-ROM, DVD and BluRay and disabled for
; hard drives. Default is true
Removable=true

; Device is emulated as supporting UNMAP. Should alwas be disabled, since writing is NOT supported
; yet. Default is false
UNMAP=false

; Device is emulated as non-rotating (e.g. SSD or NVMe), recommended to enable if image is stoed
; on a non-rotating device like a SSD or NVMe. Default is false
NoRotation=false

; Device is emulated as physically read only. No possibility to enable writes in any case. Use
; for CD-ROM, DVD and BluRay devices. Default is false
PhysicalReadOnly=false

; Device is emulated as write protected. Should always be enabled, since writing is NOT supported
; yet. Unlike physical read only, write protect state can be changed. Default is true
WriteProtect=true

; Device is emulated supporting write cache. Should always be disabled, since writing is NOT
; supported yet. Default is false
WriteCache=false